Liquid candles

ABSTRACT

A liquid candle capable of burning with a coloured flame is formed by floating a wick holder comprising a float and a wick on a body of combustible liquid within an open-top, for example, glass container, the liquid having a high flash point and containing in solution a flame-colouring amount of at least one flame-colouring additive. The float portion of the wick holder holds the wick with its lower part within the liquid and its upper part, which forms a burning end, spaced from the surface of the body of liquid to an extent which prevents ignition thereof during use. The liquid can contain a dye to enhance its appearance, and optionally also a perfume.

[ 51 Feb. 5, 1974 LIQUID CANDLES [75] Inventor: Ronald Brian Woollard,Hook,

England [73] Assignee: Prices Patent Candle Company Limited, London,England [22] Filed: Jan. 17, 1972 [21] Appl. No.: 218,248

[30] Foreign Application Priority Data Feb. 2, 1971 Great Britain3700/71 [52] 1.1.8. Cl 431/126, 431/291, 431/298, 44/59 [51] Int. Cl.F23q 2/32 [58] Field of Search 431/126, 298, 291; 44/59 [56] ReferencesCited UNITED STATES PATENTS 1,184,511 5/1916 Bourgeois 431/291 2,925,3332/1960 Thompson 44/59 2,246,346 6/1941 Carroll 431/298 2,166,881 7/1939Voss 431/126 192,294 6/1877 Simmonds 431/298 8/1966 Kohan et a1. 220/64397,011 1/1889 Leynen-l-lougaerts 431/298 3,424,540 l/l969 Swedenberg431/126 2,551,574 5/1951 Fredericks.... 431/126 3,107,511 10/1963l-Iamsag-Gars n n et al..... 431/126 3,150,510 9/1964 Klopfenstein431/126 FOREIGN PATENTS OR APPLICATIONS 449,555 7/1968 Switzerland...431/126 Primary Examiner-Carroll B. Dority, Jr.

[57] ABSTRACT 7 liquid and its upper part, which forms a burning end,

spaced from the surface of the body of liquid to an extent whichprevents ignition thereof during use. The liquid can contain a dye toenhance its appearance,

and optionally also a perfume.

11 Claims, 3 Drawing Figures LIQUID CANDLES BACKGROUND OF THE INVENTIONWith conventional solid candles containing flamecolouring additives inthe solid combustible material constituting the body of the candle tnenatural luminosity of the flame produced by combustion of the solidmaterial itself overwhelms to a greater or lesser extent the colouringaction of the additive(s). For example, a conventional wax candle burnswith a pronounced yellow flame, and the introduction of anyflame-colouring additives into the wax (other than yellow or goldenflame-colouring additives) results in little more than a coloured edgeto the flame. Other solid combustible materials, for example, solidpolyethylene glycols, as are potentially suitable for the commercialproduction of coloured flame candles of acceptable cost, albeit ofrelatively high cost compared with wax, have been found to have otherdisadvantages such as difficulty of moulding, poor flame colours yellowstill tends to predominate, and hydroscopisity, which latter gives riseto very poor storage properties.

SUMMARY OF THE INVENTION The present invention provides a new approachto the problem of providing, in a straight forward and aestheticallyacceptable manner, a candle-like device capable of burning with a trulycoloured flame. This approach is based on the concept of using acombustible liquid instead of a solid, the liquid being burned with theaid of a floating wick. The resulting combination is termed a liquidcandle." It has now been found that such a liquid candle capable ofburning with a coloured flame can be formed by providing in combinationan open-top container, a body of combustible liquid disposed therein,said liquid consisting essentially of an alcohol having a high flashpoint and the ability to burn on a wick with free burningcharacteristics andsaid liquid containing in solution a flame-colouringamount of at least one flame-colouring additive, and, floating on saidliquid, a wick holder comprising a float and a wick, the float holdingsaid wick with the lower part of said wick within said liquid and theupper part thereof projecting above said float to form an exposedburning end of said wick which is spaced from the surface of said liquidto prevent ignition thereof during use. Advantageously, said combustibleliquid is coloured by the incorporation of a light-stable colouringmatter such as one or more dyes therein, the colour of the liquid beingchosen, for example, in relation to the colour of the flame producedwhen the liquid candle is burned so as to provide an attractivecombination.

Surprisingly, it has been found that liquid candles can be formed inaccordance with the invention which are pleasing in appearance and whichburn with an intense, attractively coloured flame having none of thedisadvantages hitherto associated with the known, so-called colouredflame candles. By employing alcohols of high flash point as the basis ofthe combustible liquids, the liquids can be stored easily underconditions in which they remain stable until required for use; and anattractive, safe candle-like device can be formed by pouring the liquidinto an open-top, glass or transparent plastics container and floatingthe wick holder on the surface of the liquid. The novel and attractiveappearance of such a liquid candle, coupled with its safety and highfunctional efficiency in operation, constitutes an important advance inthe candle-manufacturing art and enables the latter to meet the largedemand for coloured flame candles which has existed for many years.

The open-top containers used in forming liquid candles in accordancewith the invention can be of any suitable size or shape as dictated byappearance considerations, and, whilst containers of transparent ortranslucent plastics material can be used, glass containers arepreferred. The wick holder can also be of any suitable size or shape,and it can comprise a float of tray or cup-like form, for example, ofcircular shape, having a central, upstanding tubular portion throughwhich the wick passes and within which the upper part of the wick isheld, which can be floated on the'surface of the combustible liquideither way up depending on its shape.

The combustible liquid used in carrying out the present inventioncontains in solution an appropriate amount of one or more additiveswhich render it capable of burning on a wick with a coloured flame. Inaddition the liquid has the following critical characteristics:

1. A high flash point which renders the liquid safe to use in a liquidcandle under any normal ambient temperature conditions likely to beencountered by users, the term high flash point" being defined herein asa flash point which is such that the liquid does not ignite and burnwhen a small flame is applied directly (i.e., in the absence of a wick)to a body of said liquid under said ambient temperature conditions. Inpractice, a minimum flash point (open cup) of C provides amplesafeguards in this respect, and accordingly liquids having a minimumflash point (open cup) of 100 are preferred. 2. An ability to burn on awick with free burning characteristics. The latter is a term wellunderstood in the art, but to avoid any misunderstanding the term isused herein to .mean an ability to continue burning for at leastone-half hour from initial ignition.

By forming said combustible liquid from an alcohol one can ensure thatit will burn on a wick in the absence of said flame-colouringadditive(s) with a flame having no pronounced luminosity, particularlyin the yellow part of the spectrum. As will be known by those in the arta yellow luminous emission can be difficult to suppress completely, butunless a liquid candle capable of burning with an intense yellow'orgolden flame, is desired, the combustible material should be such thatthe yellow content of theflame when it burns should be appreciably lessintense than that of the flame of a conventional hydrocarbon wax candleif a truly coloured flame is to be obtained. Hitherto, however, nosatisfactory way of achieving this desideratum has been found which issatisfactory, straightforward in practical application and pleasing tothe user.

DETAILED DESCRIPTION OF THE INVENTION fore burning properties arenoticeably affected, and.

this'is another advantage of ethylene glycol. In fact,

surprisingly, ethylene glycol has been found to have outstandingproperties as a combustible liquid for carrying out the presentinvention since it combines excellent burning characteristics on a wickwith the ability to give attractive, intensely coloured flames, and italso possesses high satisfactory float-support characteristics whichfacilitate the use of a floating wick holder as required to formthe-liquid candles of the invention. Glycerol and diethylene glycol canalso be used to form acceptable liquid candles, although these liquidsdo not appear to have the unique balance of properties of ethyleneglycol (ethane diol).

Any suitable liquid soluble substances capable of imparting a desiredflame colouration may be used in carrying out the present invention,particularly the metal salts which are known in the art asflamecolouring additives for solid candles, provided they are soluble insaid liquid. Preferably one or more lightstables dyes are incorporatesin the combustible liquid in order to make the liquid candle moreattractive to the user, especially when it is formed, as is preferred,

with the aid of an open top glass container for the liquid. Such dyesshould, of course, be soluble in the liquid and not all conventionalcandle body colourants are suitable in this respect. Suitability can bedetermined readily by simple experiment, but by way of illustration itis noted that the dyes marketed by Williams (Hounslow) Limited ofHounslow, Middlesex, England under the trade name Alcovar" have beenfound to be particularly suitable for use in ethylene glycol. Such dyes,in the colours green, red and violet, can be used in concentrat'ions offrom 0.0025 percent to 0.01 percent, by weight, depending on the colourintensity required; and

' they are stable to lightfo'r long periods and are without appreciableeffect on the flame colours. The glass container may be of any desiredshape consistent with the purpose it serves, and liquid candles formedin this way are particularly advantageous for household decorativepurposes and like uses. Thecombustible liquid can also be perfumed, ifdesired; any suitable perfume of acceptable cost may be used providingit is soluble in the combustible liquid and has no deleterious affect onthe burning characteristics thereof, and does not give rise to anyobjectionable end products, for example, odourwise when burned. By wayof illustration it can be mentioned that a perfume marketed by Dragoca(Great Britain) Ltd., of Lady Lane Industrial Estate, Hadleigh, Essex,England, under the trade designation ER 0/0098 has givensatisfactoryresults in ethylene glycol based combustible liquids.

-Many flame-colouring chemicals are known in the art in connection withprior proposals for making conventional (solid) candles for burning witha coloured flame, and the nature and characteristics of such chemicalsand the flame colourations achievable with various metals are well knownin the art. However, the use of a combustible liquid opens up thepossibility of using, as additives in accordance with the presentinvention, other compounds of the metals hitherto used, provided theselected additive (s) will dissolve, in the concentration(s) needed, inthe combustible liquid; consequently, the present invention is in no waylimited to the use of conventional flame-colouring additives theproperties of which are necessarily dictated by the need forcompatibility withthe solid candle material. The chemical(s) used in aparticular case will depend on the flame colour required, and therelative cost and ease of handling when a choice is available. Examplesinclude boric acid and salts of many metals, for example, lithium,sodium, potassium, strontium, and barium. The salts may be, for example,acetates (which are often particularly suitable), chlorides, nitrates,citrates, tartrates and carbonates. The ability to dissolve theadditive(s) in the liquid in the cold or with only slight heating isadvantageous. Mixtures of flame-colouring chemicals may be used in orderto produce desired colours or novel, two tone affects. The concentrationof the flame-colouring chemical(s) required will depend on theparticular chemical(s) used, but can be determined readily by trial. Ingeneral, the range of concentration is quite wide, Although from thepoint of view of achieving clean burning, it is preferable to use thesmallest amount consistent with obtaining a good colouration. Guidancein regard to the quantities of additives which can be used will beobtained from the formulations exemplified hereinafter. However, thefollowing additives in the concentration ranges quoted have been foundto be particularly effective with ethane diol for producing flamecolours which are particularly popular with users of the liquid candlesof the present invention: I

Green: 1.3 to 1.7% wt. of boric acid Red: 0.2 to 0.4% wt. of lithiumacetate, preferably together with an equal amount of potassium chlorideLilac: 0.2 to 0.5% wt. of potassium chloride Combustible liquidscontaining one or more flamecolouring additives and optionally also oneor more dyes may be supplied to users in capped containers from whichthe liquid can be poured into any suitable open-topped container of theuser's choice to form, with a floating wick holder, a liquid candle inaccordance with the invention. For asthetic appeal the capped containermay be shaped, and perhaps also textured, to look like a conventionalsolid candle. A wick holder, together with a wick which is convenientlyalready fitted thereto, can be supplied to'the user together with thecapped container of combustible liquid, together, if desired, with aglass-open-top container. The wick holder can be of a plastics material,for example, a urea formaldehyde resin or it can be of metal, forexample, aluminium. Whilst the size, shape and dimensions of the holdershould be such that it will float safely on the combustible liquid, adegree of decoration is advantageous from the appearance aspect. Forexam ple, the base of the wick holder can be cone-shaped to some extent.Preferably, the wick holder is made from a non-inflammable material, andaluminium is preferred; in such case the aluminium holder can beanodised in a variety of colours to enhance its appearance.

Alternatively, the wick holder can be made of glass. Although the wickholder can be designed so that it can also form a cap for the containerof combustible liquid, it is considered preferable to supply separatewick holders.

One example of a suitable form of wick holder is illustrated in thedrawing accompanying the provisional specification, in which FIG. 1shows a perspective side view and FIG. 2 a plan view. The wick holdercomprises a float in the form of a cap 3 having an upstanding tubularportion 4 for holding the wick 5. The base 6 of the cap 3 to which theportion 4 is secured, or of which is forms an integral part, as, forexample, when the cap is moulded in a plastics material, is apertured toenable the wick 5 to pass through it. In use a short length of the wick5 protrudes from the tubular portion 4 to form a burning end. If thewick holder is used as a screw cap for a container of liquid, the cap 3is provided with an internal screw thread, and when in use as screw capa plug or like seal is inserted in the cap 3 to seal off the tubularportion 4, thereby preventing spillage of the liquid and access ofatmosphereic air (in particular moisture therefrom) to the liquid.

A preferred form of wick holder is illustrated in FIG. 3 of theaccompanying drawing. The wick holder comprises a float in the form of atray 3 having a dished base portion 3A of cone shape to enhance theappearance of the float. An upstanding tubular portion 4 is provided forholding the wick 5, and the upper end of the tubular portion 4 islocated below the level of the rim 3B of the tray 3. Advantageously thewick holder is of anodised aluminium and the following dimensions of atypical wick holder can be given by way of illustration as follows: traydiameter: lVzinches; tray height: three-fourths inch, plus up toone-fourth inch for the dished base portion; height of tubular portion:one-half inch; and diameter of tubular portion: one-fourth inch(outside) and one-eighth inch (inside).

The wick holder can be of other forms or shapes depending onrequirements. It is envisaged that one or more wick holders can bemarketed in combination with a container of .combustible liquid and anopen-top glass as a presentation pack for customers.

Certain flame colouring chemicals, for example, lithium nitrate, lithiumacetate, potassium chloride and sodium chloride can produce anaccumulation of incombustible ash on the wick during burning and theshape any material falling from the wick is caught and prevented fromcoming into contact with the combustible liquid where it might act as asecondary wick. It is also possible by simply pulling more wick throughthe tubular portion of the wick holder to restore normal burningcharacteristics if, after a period of burning, accumulations on thewick, affect the performance of the liquid candle; normally, the burningtime before any retrimming is needed will be at least one hour dependingon the flame-colouring additive(s) used, and with some additives and/orconcentrations of additives it is not really necessary at all. Theoptimum combinations and concentrations of the various additives whichgive the desired flame colourations with the minimum of ash formation onthe wick can be ascertained by experiment.

The wick itself can consist of conventional cotton candlewick or taperwhich has not been treated with any of the wick conditioning chemicalsnormally used in candle manufacture which might otherwise introducecontaminants affecting the flame colour. (In any case such wickconditioning would be an unnecessary in carrying out the presentinvention). A loose plait or twisted taper cotton is preferred.

Liquid candles in accordance with the present invention can be expectedto have many hours of life. For example, a 100 ml. of combustible liquidcan burn for up to about 8 hours depending on the flame size, which canbe controlled by adjusting the length of wick showing above the tubularportion of the wick holder. In the latter respect about one-fourth inchgives a good result. In order to avoid a falling offin performance aftera period of use due to absorption by the combustible liquid of thefloating wick holder is advantageously such that of moisture from theair, it is advisable to keep the glass or other open-topped container ofthe candle covered when not in use.

The present invention is illustrated by the seven typi-v calformulations of the following examples. These are all based oncommercial ethylene glycol (ethane diol), and the specified additiveswere dissolved therein in the cold or, if necessary, by heating:

EXAMPLE 1 ETHANE DlOL BORlC AClD l-l0% wt.

plus a green dye.

This formulation gives a bright green flame. Large amounts of boric acidshould be avoided since these tend to produce a white film on the sideof the glass after prolonged burning which looks rather unsightly. Theextent of this film depends largely on the shape of the glass used, buta concentration of boric acid of 2 percent wt. or less, andadvantageously about 1.5 percent wt., is to be'preferred. I

EXAMPLE 2 ETHANE DlOL LlTHlUM ACETATE 0.l5% wt.

EXAMPLE 3 99% wt. 0.5 to 1% wt., preferably 0.5% wt.

ETHANE DlOL POTASSIUM CHLORIDE plus a lilac dye.

This formulation gives a lilac colour, which becomes increasingly vividafter about 10 minutes burning. Ash can build up on the wick, and thereduction in potassium chloride concentration to 0.5 percent wt. reducesthis tendency while still maintaining a satisfactory colouration. I

EXAMPLE 4 ETHANE DlOL 99.9% wt.

O.l% wt.

SODIUM CHLORIDE plus an orange 'dye.

This formulation gives a bright golden flame. Larger amounts of sodiumchloride e.g., 0.2 percent wt. lead to more ash formation and are bestavoided.

EXAMPLE 5 ETHANE DlOL 99.2% wt. BORIC ACID 0.5% wt. LITHIUM ACETATE 0.3%wt.

This formulation gives a flame with an orange/red interior and a greenedging.

This formulation gives a golden flame with a green edge.

EXAMPLE 7 ETHANE DlOL 99.5% wt. POTASSIUM CARBONATE This formulationgives alilac flame.

EXAMPLE 8 Similar results to those quoted above in regard to Examples lto 7 may be obtained by substituting for the ethane diol other alcoholssuch as glycerol.

The amounts of flame-colouring additives used with such other alcoholsare essentially similar to those quoted for ethane diol, optimum amountswithin the ranges quoted being readily determined by simple experimenton the basis of the colour and intensity of colour required in relationto cost considerations and ease of forming the required alcoholsolutions thereof.

I claim as my invention:

1. A liquid candle capable of burning with a coloured flame whichcomprises a. an open top container containing a body of combustibleliquid of high flash point therein,

b. said liquid consisting essentially of an alcohol having a minimumflash point of 100C. and the ability to burn on a wick with free burningcharacteristics and c. said liquid containing, in solution, aflame-coloring amount of an ash producing flame coloring additivecontaining a metal salt, and

d. floating on said liquid, a wick holder comprising a float and a wick,

e. the float having adished-base portion floating with its uppermostsurface clear of said liquid, said base portion including an upstandingwall portion extending therefrom and an upstanding tubular portionholding said wick with the lower part of said wick within said liquidand the upper part of said wick projecting about said float to form anexposed burning end of said wick which is spaced from the surface ofsaid liquid to prevent ignition thereof during use.

2. A liquid candle as claimed in claim 1, wherein said liquid alsocontains in solution light stable dye colouring matter. 7

3. A liquid candle as claimed in claim 1, wherein said liquid alsocontains in solution a perfume.

4. A liquid candle as claimed in claim 1, wherein said liquid containsat least one metal acetate as flamecolouring additive.

5. A liquid candle, as in claim 1, wherein the combustible liquid isethane diol.

6. A liquid candle, as in claim 5, wherein theethane diol contains from1.3 to 1.7 percent by weight of boric acid as a flame-coloring additive.

7. A liquid candle, as in claim 5, wherein the ethane diol contains from0.2 to 0.4 percent by weight of lithium acetate as a flame-coloringadditive.

8. A liquid candle, as in claim 7, wherein the ethane diol contains from0.2 to 0.4 percent by weight of potassium chloride asan additionalflame-coloring additive.

9. A liquid candle, as in claim 5, wherein the ethane diol contains from0.2 to 0.5 percent by weight of potassium chloride as a flame coloringadditive.-

10. A liquid candle, as in claim 1, wherein the float has a sidewallupstanding from the base portion to a height greater than the tubularportion.

11. A liquid candle, as in claim 1, wherein the base of the float is aconvex conical form.

2. A liquid candle as claimed in claim 1, wherein said liquid alsocontains in solution light stable dye colouring matter.
 3. A liquidcandle as claimed in claim 1, wherein said liquid also contains insolution a perfume.
 4. A liquid candle as claimed in claim 1, whereinsaid liquid contains at least one metal acetate as flame-colouringadditive.
 5. A liqUid candle, as in claim 1, wherein the combustibleliquid is ethane diol.
 6. A liquid candle, as in claim 5, wherein theethane diol contains from 1.3 to 1.7 percent by weight of boric acid asa flame-coloring additive.
 7. A liquid candle, as in claim 5, whereinthe ethane diol contains from 0.2 to 0.4 percent by weight of lithiumacetate as a flame-coloring additive.
 8. A liquid candle, as in claim 7,wherein the ethane diol contains from 0.2 to 0.4 percent by weight ofpotassium chloride as an additional flame-coloring additive.
 9. A liquidcandle, as in claim 5, wherein the ethane diol contains from 0.2 to 0.5percent by weight of potassium chloride as a flame-coloring additive.10. A liquid candle, as in claim 1, wherein the float has a sidewallupstanding from the base portion to a height greater than the tubularportion.
 11. A liquid candle, as in claim 1, wherein the base of thefloat is a convex conical form.